Could regular fuel be better then premium?

[M_Bolc]

(...) designed for 87 octane and using higher octane fuel can cause other issues.

Actually, higher octane than required won't do any damage.

[wooflepoof]

My friend who enjoys wasting his parents money ONLY puts Shell Vpower in his Corolla when he can. Otherwise nothing less than 93 will do. Hes also the kid that curbed our friends Mazda 3 claiming he 'oversteered' and hit the REAR RIGHT TIRE on a RIGHT HAND TURN in a MAZDA 3. We humored him cuz it only resulted in a flat. But I digress

my cars book recommends 91+ but it says it can take 87. I've tried all 3 and there's a noticeable difference between 87 and 91 but not 91 and 93.

[IceBone]

My car has a Direct Injection system with very high compression, so needs 95+ octane, but I've found that I get better fuel consumption (more than enough to counter the price increase) if I tank up on 98 or 100.

[argatoga]

Both my cars get 87 (US) octane, (yes even my 182hp per liter MG gets the basic stuff).

[Das_Idiot]

Actually, higher octane than required won't do any damage.

yeah I mean lower, not higher. If you use lower octane than what's required you can get early combustion of the fuel which most people know as 'knocking' and this is bad, mmkay.

but you are correct, using higher octane fuel won't do any damage to the engine, it just won't give any benefit either as the compression ratio is so low in these cases that you won't get any benefit. You do however get to spend more money for what (to you) amounts to the same thing... and some people are weird/stoopid like that.

and no, higher octane fuel won't 'burn cleaner' or anything like that. (whatever the hell that means).

[difiCa]

and no, higher octane fuel won't 'burn cleaner' or anything like that. (whatever the hell that means).

Wouldn't it be exactly the opposite? I mean, if higher octane fuel can resist burning in a low compression engine so well that it combusts only partially, leaving finite amounts of it behind, wouldn't that count as "burning dirtier"?

[IceBone]

There's a difference between autocombustion from excessive pressure (which a higher octane rating prevents) and assisted combustion, i.e. using spark plugs.

[Stefano1337]

Isn't it true though that if you put normal petron in your car after you have filled it up with optimax or something, your engine management might get confused?

[Spectre]

and no, higher octane fuel won't 'burn cleaner' or anything like that. (whatever the hell that means).

At least over here, sometimes higher octane fuel "burns cleaner" because they have a much larger percentage of detergents in them. Nothing to do with the actual petrol, it's the additive package.

[MattD1zzl3]

So me running down to murreys and getting that 5gallon drum of 118 octane is a waste of money than?

[Spectre]

Race gas is another creature entirely. Everyone here is talking about pump gas.

[MattD1zzl3]

118 + Camaro = Surrounding Air smells like jesus.

EDIT: I can get 110 from the pump here in florida, nyah nyah nyah nyah.

[Spectre]

I can get 120, what's your point? Its still not "normal" pump gas.

[MattD1zzl3]

O.o 120 from a normal chain gas station? TEH?!?!?

[Spectre]

There's a Sunoco Race Fuels station nearby and if that wasn't enough, there's a damn airport.

[wooflepoof]

God Bless Texas

[MattD1zzl3]

haha, ill convert a car to run on avgas one of these days...